Skull Flashcards
The skull has ______ bones, excluding the ossicles of the ear.
22
Except for the mandible, which forms the lower jaw, the bones of the skull are attached to each other by sutures, are immobile, and form the ______.
cranium
The cranium can be subdivided into:
• an upper domed part (the ______), which covers the cranial cavity containing the brain,
• a ______ that consists of the floor of the cranial cavity, and
• a lower anterior part—the facial skeleton (______).
calvaria, base, viscerocranium
The bones forming the calvaria are mainly the paired ______ and ______ bones, and parts of the unpaired ______, ______, and ______ bones.
temporal, parietal, frontal, sphenoid, occipital
The bones forming the base of the cranium are mainly parts of the ______, ______, and ______ bones.
sphenoid, temporal, occipital
The bones forming the facial skeleton are the paired ______ bones, ______ bones, ______ bones, ______ bones, ______ and ______ and the unpaired ______.
nasal, palatine, lacrimal, zygomatic, maxillae, inferior nasal conchae, vomer
The ______ is not part of the cranium nor part of the facial skeleton.
mandible
The ______ of the skull includes the forehead superiorly, and, inferiorly, the orbits, the nasal region, the part of the face between the orbit and the upper jaw, the upper jaw, and the lower jaw.
anterior view
The forehead consists of the ______, which also forms the superior part of the rim of each orbit.
frontal bone
Just superior to the rim of the orbit on each side are the raised ______.
superciliary arches
Superciliary arches are more pronounced in ______.
men
Between the superciliary arches is a small depression (the ______).
glabella
Clearly visible in the medial part of the superior rim of each orbit is the ______ (______).
supra-orbital foramen, supra-orbital notch
Medially, the ______ bone projects inferiorly forming a part of the medial rim of the orbit.
frontal
Laterally, the ______ process of the frontal bone projects inferiorly forming the upper lateral rim of the orbit.
zygomatic
The zygomatic process of the frontal bone articulates with the ______ process of the zygomatic bone.
frontal
The lower lateral rim of the orbit, as well as the lateral part of the inferior rim of the orbit is formed by the ______ (the ______).
zygomatic bone, cheekbone
Superiorly, in the nasal region the paired ______ bones articulate with each other in the midline, and with the frontal bone superiorly.
nasal
The center of the frontonasal suture formed by the articulation of the nasal bones and the frontal bone is the ______.
nasion
Laterally, each nasal bone articulates with the ______ process of each maxilla.
frontal
Inferiorly, the ______ is the large opening in the nasal region and the anterior opening of the nasal cavity.
piriform aperture
It is bounded superiorly by the nasal bones and laterally and inferiorly by each maxilla.
piriform aperture
Visible through the piriform aperture are the fused ______, forming the lower part of the bony ______ and ending anteriorly as the ______, and the paired ______.
nasal crests, nasal septum, anterior nasal spine, inferior nasal conchae
The part of the face between the orbit and the upper teeth and each upper jaw is formed by the paired ______.
maxillae
Superiorly, each ______ contributes to the inferior and medial rims of the orbit.
maxilla
Laterally, the ______ of each maxilla articulates with the zygomatic bone and medially, the ______ of each maxilla articulates with the frontal bone.
zygomatic process, frontal process
Inferiorly, the part of each maxilla, lateral to the opening of the nasal cavity, is the ______ of the maxilla.
body
On the anterior surface of the body of the maxilla, just below the inferior rim of the orbit, is the ______.
infra-orbital foramen
Inferiorly, each maxilla ends as the ______, which contains the teeth and forms the upper jaw.
alveolar process
The lower jaw (______) is the most inferior structure in the anterior view of the skull.
mandible
The mandible consists of the ______ of the mandible anteriorly and the ______ of the mandible posteriorly.
body, ramus
The body of the mandible and the ramus of the mandible meet posteriorly at the ______ of the mandible.
angle
The body of the mandible is arbitrarily divided into two parts:
– The lower part is the ______ of the mandible.
– The upper part is the ______ of the mandible.
base, alveolar part
The ______ of the mandible contains the teeth and is resorbed when the teeth are removed.
alveolar part
The base of the mandible has a midline swelling (the ______) on its anterior surface where the two sides of the mandible come together.
mental protuberance
Just lateral to the mental protuberance, on either side, are slightly more pronounced bumps (______).
mental tubercles
Laterally, a ______ is visible halfway between the upper border of the alveolar part of the mandible and the lower border of the base of the mandible.
mental foramen
Continuing past the mental foramen is a ridge (the ______) passing from the front of the ramus onto the body of the mandible.
oblique line
The ______ is a point of attachment for muscles that depress the lower lip.
oblique line
The ______ of the skull consists of the lateral wall of the cranium, which includes lateral portions of the calvaria and the facial skeleton, and half of the lower jaw.
lateral view
Bones forming the lateral portion of the calvaria include the ______, ______, ______, ______, and ______ bones.
frontal, parietal, occipital, sphenoid, temporal
Bones forming the visible part of the facial skeleton (lateral view) include the ______, ______, and ______ bones.
nasal, maxilla, zygomatic
The ______ forms the visible part of the lower jaw (lateral view).
mandible
The lateral portion of the calvaria begins anteriorly with the ______ bone.
frontal
In upper regions, the frontal bone articulates with the parietal bone at the ______.
coronal suture
The parietal bone then articulates with the occipital bone at the ______.
lambdoid suture
In lower parts of the lateral portion of the calvaria, the frontal bone articulates with the ______, which then articulates with the parietal bone at the ______, and with the anterior edge of the temporal bone at the ______.
greater wing of the sphenoid bone, sphenoparietal suture, sphenosquamous suture
The junction where the frontal, parietal, sphenoid, and temporal bones are in close proximity is the ______.
pterion
The clinical consequences of a skull fracture in this area can be very serious.
pterion
The bone in the pterion is particularly thin and overlies the anterior division of the middle meningeal artery, which can be torn by a skull fracture in this area, resulting in an ______.
extradural hematoma
The final articulation across the lower part of the lateral portion of the calvaria is between the temporal bone and the occipital bone at the ______.
occipitomastoid suture
A major contributor to the lower portion of the lateral wall of the cranium is the ______ bone.
temporal
The temporal bone consists of several parts:
squamous part, zygomatic process, tympanic part, petromastoid part
The ______ of the temporal bone has the appearance of a large flat plate, forms the anterior and superior parts of the temporal bone, contributes to the lateral wall of the cranium, and articulates anteriorly with the greater wing of the sphenoid bone at the sphenosquamous suture, and with the parietal bone superiorly at the squamous suture.
squamous part
The ______ of the temporal bone is an anterior bony projection from the lower surface of the squamous part of the temporal bone that initially projects laterally and then curves anteriorly to articulate with the temporal process of the zygomatic bone to form the ______.
zygomatic process, zygomatic arch
Immediately below the origin of the zygomatic process from the squamous part of the temporal bone is the tympanic part of the temporal bone, and clearly visible on the surface of this part is the ______ leading to the ______ (ear canal).
external acoustic opening, external acoustic meatus
The petromastoid part of the temporal bone, which is usually separated into a ______ and a ______ for descriptive purposes.
petrous part, mastoid part
The ______ is the most posterior part of the temporal bone, and is the only part of the petromastoid part of the temporal bone seen on a lateral view of the skull.
mastoid part
The mastoid part is continuous with the squamous part of the temporal bone anteriorly, and articulates with the parietal bone superiorly at the ______, and with the occipital bone posteriorly at the ______.
parietomastoid suture, occipitomastoid suture
The parietomastoid and occipitomastoid sutures are continuous with each other, and the parietomastoid suture is continuous with the ______.
squamous suture
Inferiorly, a large bony prominence (the ______) projects from the inferior border of the mastoid part of the temporal bone. This is a point of attachment for several muscles.
mastoid process
Medial to the mastoid process, the ______ projects from the lower border of the temporal bone.
styloid process
The bones of the viscerocranium visible in a lateral view of the skull include the ______, ______, and ______ bones.
nasal, maxilla, zygomatic
The ______ with its alveolar process containing teeth forming the upper jaw; anteriorly, it articulates with the nasal bone; superiorly, it contributes to the formation of the inferior and medial borders of the orbit; medially, its frontal process articulates with the frontal bone; laterally, its zygomatic process articulates with the zygomatic bone.
maxilla
The ______, an irregularly shaped bone with a rounded lateral surface that forms the prominence of the cheek, is a visual centerpiece in this view— medially, it assists in the formation of the inferior rim of the orbit through its articulation with the zygomatic process of the maxilla; superiorly, its frontal process articulates with the zygomatic process of the frontal bone assisting in the formation of the lateral rim of the orbit; laterally, seen prominently in this view of the skull, the horizontal temporal process of the zygomatic bone projects backward to articulate with the zygomatic process of the temporal bone and so form the zygomatic arch.
zygomatic bone
Usually a small foramen (the ______) is visible on the lateral surface of the zygomatic bone.
zygomaticofacial foramen
A ______ foramen is present on the medial deep surface of the bone.
zygomaticotemporal
The final bony structure visible in a lateral view of the skull is the ______.
mandible
Inferiorly in the anterior part of the lateral view, the mandible consists of the anterior ______ of the mandible, a posterior ______ of the mandible, and the ______ of the mandible where the inferior margin of the mandible meets the posterior margin of the ramus
body, ramus, angle
The teeth are in the ______ of the body of the mandible and the mental protuberance is visible in the lateral view.
alveolar part
The ______ is on the lateral surface of the body of the mandible, and on the superior part of the ramus of the mandible ______ and ______ processes extend upward.
mental foramen, condylar, coronoid
The ______ process is involved in articulation of the mandible with the temporal bone, and the ______ process is the point of attachment for the temporalis muscle.
condylar, coronoid
The ______, ______, and ______ bones are seen in the posterior view of the skull.
occipital, parietal, temporal
Centrally the flat or ______ of the occipital bone is the main structure in the posterior view of the skull.
squamous part
Along the lambdoid suture small islands of bone (______ or ______) may be observed.
sutural bones, wormian bones
Several bony landmarks are visible on the ______ bone.
occipital
On the occipital bone, there is a midline projection (the ______) with curved lines extending laterally from it (______).
external occipital protuberance, superior nuchal lines
The most prominent point of the external occipital protuberance is the ______.
inion
About 1 inch (2.5 cm) below the superior nuchal lines two additional lines (the ______) curve laterally.
inferior nuchal lines
Extending downward from the external occipital protuberance is the ______.
external occipital crest
Laterally, the temporal bones are visible in the posterior view of the skull, with the ______ processes being the prominent feature.
mastoid
On the inferomedial border of each mastoid process is a notch (the ______), which is a point of attachment for the posterior belly of the digastric muscle.
mastoid notch
The ______ bone, ______ bones, and ______ bone are seen in a superior view of the skull. These bones make up the superior part of the ______ or the ______ (skullcap).
frontal, parietal, occipital, calvaria, calva
The unpaired frontal bone articulates with the paired parietal bones at the ______.
coronal suture
The two parietal bones articulate with each other in the midline at the ______.
sagittal suture
The parietal bones articulate with the unpaired occipital bone at the ______.
lambdoid suture
The junction of the sagittal and coronal sutures is the ______, and the junction of the sagittal and lambdoid sutures is the ______.
bregma, lambda
The only foramina visible in the superior view of the skull may be the paired ______, posteriorly, one on each parietal bone just lateral to the sagittal suture.
parietal foramina
The bones making up the calvaria are unique in their structure, consisting of dense internal and external tables of compact bone separated by a layer of spongy bone (the ______).
diploë
The ______ of the skull is seen in the inferior view and extends anteriorly from the middle incisor teeth posteriorly to the superior nuchal lines and laterally to the mastoid processes and zygomatic arches.
base
For descriptive purposes the base of the skull is often divided into:
• an ______ which includes the teeth and the hard palate,
• a ______, which extends from behind the hard palate to the anterior margin of the foramen magnum, and
• a ______, which extends from the anterior edge of the foramen magnum to the superior nuchal lines.
anterior part, middle part, posterior part
The main features of the anterior part of the base of the skull are the ______ and the ______.
teeth, hard palate
The teeth project from the ______ of the two maxillae.
alveolar processes
These processes are together arranged in a U-shaped alveolar arch that borders the hard palate on three sides.
alveolar processes
The hard palate is composed of the ______ of each maxilla anteriorly and the ______ of each palatine bone.
palatine processes, horizontal plates
The paired palatine processes of each maxilla meet in the midline at the ______, the paired maxillae and the paired palatine bones meet at the ______, and the paired horizontal plates of each palatine bone meet in the midline at the ______.
intermaxillary suture, palatomaxillary suture, interpalatine suture
The ______ fossa in the anterior midline immediately posterior to the teeth, the walls of which contain incisive foramina (the openings of the ______, which are passageways between the hard palate and nasal cavity);
incisive, incisive canals
The ______ foramina near the posterolateral border of the hard palate on each side, which lead to ______.
greater palatine, greater palatine canals
Just posterior to the greater palatine foramina, the ______ foramina in the pyramidal process of each palatine bone, which lead to ______.
lesser palatine, lesser palatine canals
A midline pointed projection (the ______) in the free posterior border of the hard palate.
posterior nasal spine
The middle part of the base of the skull is complex:
• Forming the anterior half are the ______ and ______ bones.
• Forming the posterior half are the ______ and paired ______ bones.
vomer, sphenoid, occipital, temporal
Anteriorly, the small ______ is in the midline, resting on the sphenoid bone. It contributes to the formation of the bony nasal septum separating the two choanae.
vomer
Most of the anterior part of the middle part of the base of the skull consists of the ______ bone.
sphenoid
The sphenoid bone is made up of a centrally placed ______, paired ______ and ______ projecting laterally from the body, and two downward projecting ______ immediately lateral to each choana.
body, greater, lesser wings, pterygoid processes
Three parts of the sphenoid bone, the ______, ______, and ______, are seen in the inferior view of the skull.
body, greater wings, pterygoid processes
The ______ of the sphenoid is not seen in the inferior view.
lesser wing
The ______ of the sphenoid is a centrally placed cube of bone containing two large air sinuses separated by a septum.
body
Extending downward from the junction of the body and the greater wings of the sphenoid bone are the ______.
pterygoid processes
Each of the pterygoid processes consists of a narrow ______ and broader ______ separated by the ______.
medial plate, lateral plate, pterygoid fossa
Each medial plate of the pterygoid process ends inferiorly with a hook-like projection, the ______, and divides superiorly to form the small, shallow ______.
pterygoid hamulus, scaphoid fossa
Just superior to the scaphoid fossa, at the root of the medial plate of the pterygoid process is the opening of the ______, which passes forward from near the anterior margin of the foramen lacerum.
pterygoid canal
Lateral to the lateral plate of the pterygoid process is the ______ of the sphenoid, which not only forms a part of the base of the skull but also continues laterally to form part of the lateral wall of the skull.
greater wing
Important features visible on the surface of the greater wing in an inferior view of the skull are the ______ and the ______ on the posterolateral border extending outward from the upper end of the lateral plate of the pterygoid process.
foramen ovale, foramen spinosum
In the posterior half of the middle part of the base of the skull are the occipital bone and the paired ______.
temporal bones
The occipital bone, or more specifically its ______, is in the midline immediately posterior to the body of the sphenoid.
basilar part
The basilar part of the occipital bone extends posteriorly to the ______ and is bounded laterally by the temporal bones.
foramen magnum
Prominent on the basilar part of the occipital bone is the ______, a bony protuberance for the attachment of parts of the pharynx to the base of the skull.
pharyngeal tubercle
Immediately lateral to the basilar part of the occipital bone is the ______ of the petromastoid part of each temporal bone.
petrous part
Wedge-shaped in its appearance, with its apex anteromedial, the ______ of the temporal bone is between the greater wing of the sphenoid anteriorly and the basilar part of the occipital bone posteriorly.
petrous part
The apex of the petrous part of the temporal bone forms one of the boundaries of the ______, an irregular opening filled in life with cartilage.
foramen lacerum
Posterolateral from the foramen lacerum along the petrous part of the temporal bone is the large circular opening for the ______.
carotid canal
Between the petrous part of the temporal bone and the greater wing of the sphenoid is a groove for the cartilaginous part of the ______ (______).
pharyngotympanic tube, auditory tube
Just lateral to the greater wing of the sphenoid is the ______ of the temporal bone, which participates in the temporomandibular joint.
squamous part
The squamous part of the temporal bone contains the ______, which is a concavity where the head of the mandible articulates with the base of the skull.
mandibular fossa
An important feature of the articulation of the head of the mandible and the base of the skull is the prominent ______, which is the downward projection of the anterior border of the mandibular fossa.
articular tubercle
The ______ is the major bony element of the posterior part of the base of the skull.
occipital bone
The occipital bone has four parts organized around the ______, which is a prominent feature of this part of the base of the skull and through which the brain and spinal cord are continuous.
foramen magnum
The parts of the occipital bone are the ______, which is posterior to the foramen magnum, the ______, which are lateral to the foramen magnum, and the ______, which is anterior to the foramen magnum.
squamous part, lateral parts, basilar part
The ______ and ______ of the occipital bone are components of the posterior part of the base of the skull.
squamous, lateral parts
The most visible feature of the squamous part of the occipital bone when examining the inferior view of the skull is a ridge of bone (the ______), which extends downward from the external occipital protuberance toward the foramen magnum.
external occipital crest
The ______ arc laterally from the midpoint of the external occipital crest.
inferior nuchal lines
On each anterolateral border of the foramen magnum are the rounded ______.
occipital condyles
These paired structures articulate with the atlas (vertebra CI).
occipital condyles
Posterior to each condyle is a depression (the ______) containing a ______, and anterior and superior to each condyle is the large ______.
condylar fossa, condylar canal, hypoglossal canal
Lateral to each hypoglossal canal is a large, irregular ______ formed by opposition of the jugular notch of the occipital bone and jugular notch of the temporal bone.
jugular foramen
Laterally in the posterior part of the base of the skull is the ______ bone.
temporal
The parts of the temporal bone seen in the lateral posterior part of the base of the skull are the ______ of the petromastoid part and the ______.
mastoid part, styloid process
The lateral edge of the mastoid part is identified by the large cone-shaped ______ projecting from its inferior surface. This prominent bony structure is the point of attachment for several muscles.
mastoid process
On the medial aspect of the mastoid process is the deep ______, which is also an attachment point for a muscle.
mastoid notch
Anteromedial to the mastoid process is the needle-shaped ______ projecting from the lower border of the temporal bone. It is also a point of attachment for numerous muscles and ligaments.
styloid process
Finally, between the styloid process and the mastoid process is the ______.
stylomastoid foramen